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By KENNETH CROPPER

USUALLY we forget about the things which move along smoothly. There are no causes for worry when there are no troubles. But when troubles arise we must put forth some thought and effort to alleviate them. No one "worries about his automobile until it begins to knock, develop flat tires, or refuses to start. However, when these ailments become apparent we get wide awake on the spot, and do our best to repair the car. So we find ourselves now. The old bus seems to hit all the ditches. There is rough ground on all sides and none of us is able to do anything toward improvement. A state of pessimism stares us in the face, and there is sufficient cause for it. With lead at 3.75 cents, copper about 8 cents, zinc under 4 cents, -and silver about 26 cents, one has a reason for grief. When we think of the 5000 or less men employed in Utah mines and smelters in 1931, as compared with about 12,000 in 1929, the calamity seems even worse. In view of the present economic crisis we cannot even think of new men getting a job.

Jan 1, 1931

By Karl Berger, Michael Steinkogler

The evolution in Metal Cutting: Inventors around the world have been successfully developing innovations for decades, but only some of these developments have had „GAME CHANGING“ potential. One of these innovations is the new developed saw blade LINCUT®, a patented changing system that paves the way for a fundamental reorientation of the entire saw blade industry worldwide through a simple and economical concept for rolling mills or heavy forging lines. Cost efficiency starts with the raw material: Circular saws equipped with a standard saw blade are expected to have a necessary 2 percent standstill per year due to required tool changing. The applied technology reduces this unnecessary loss of production by more than 50%. The ROI can therefore be reached faster which immediately lowers your production costs. No matter what material, conventional carbon steel or highly alloyed stainless steel, the coating and shape of carbide plates is perfected for extended tool life up to 25% with increased performance. Due to LINSINGERs own tool-technology-centre in Austria specialized in research and development of tools, constantly expanding R&D activities, best results are achieved in quality and cost efficiency: a (r)evolution in metal cutting.

Oct 1, 2019

By K S. Park, J K. Kim, J H. Park, Y Su

The present study investigates the possibility of the direct removal of oxygen from the Ti-30Ni (wt per cent) alloy melt through the thermodynamic equilibrium reactions at 1623 K in the vertical tube furnace. The deoxidation efficiency of Ti-Ni alloy melt by adding different contents of metallic calcium (Ca) as a deoxidant was evaluated with the binary CaF2-MgCl2 flux. The thermodynamic equilibrium experiments showed that the total oxygen content in the alloy decreased from about 650 ppm to 350 ppm when 3.5 wt per cent Ca was added to the Ti-30Ni (wt per cent) alloy. Alternatively, the effect of flux composition in the CaF2-MgCl2 flux on the oxygen content was also investigated at 1623 K. Therefore, the effect of binary flux systems on the deoxidation ability was compared at 1623 K. According to the results, the flux system with 80 per centCaF2– 20 per centMgCl2 exhibited the best deoxidation capability, ie total oxygen content in the alloy reduced from 1450 to 550 ppm.

Aug 21, 2024

By J. T. Winkelmann

The Mineral Park Mine is an open pit copper-molybdenum mine located in northwestern Arizona, approximately twenty miles northwest of Kingman, Arizona. The concentrating facility has been regarded, with the expansion in 2011, as a plant capable of treating fifty thousand short tons of feed per day for the mixture of supergene and hypogene ores available. The grinding circuit consists of two 32? x 14? SAG mills and four 20? x 28? ball mills. As ores became harder with greater depth in the adjacent pit areas, however, the SAG mills became severely throughput limited. The traditional treatment for similar properties is the installation of a recycle pebble crushing circuit. Because the cost of such an installation is quite elevated, and preliminary testing and research was inconclusive regarding the predicted throughput increases, management and technical personnel set out to find another solution to the problem. The result entailed a redesign of SAG lifters/liners and a nearly unique circuit change which was, at best, a difficult step that defied current grinding logic. This paper describes these changes, events leading up to them, and the results.

Feb 23, 2014

By E. J. Gleim

In the movement of self-controlled direct-current machinery, particularly shortwall cutting, machines, from one place to another in coal mires, "nipping" or it stinging" has been practiced quite commonly. These terms refer to the method of obtaining current for propelling or tramming the machines along trolley haulageways by sliding the trolley trip (hook or nip), which terminates one conductor of the trailing cable, along the trolley wire. This is usually done by the machine operator or runner while sitting on the machine truck and holding the nip terminal against the trolley wire as the machine travels along the rails. This procedure is objectionable for several reasons. Under the best conditions, the area of contact between the nip and trolley wire is snail end, consequently, sparking and flashing ore most likely to be continuous as the machine proceeds. This is undesirable, not only because of the detrimental effect of electric flashes upon eyesight, but because of the pitting and roughening the trolley wheels which decrease the efficiency of current collection by locomotive trolley wheels and shoes and at the same time shorten their useful life by increased wear.

Jan 1, 1939

By W. H. Langer

Around the beginning of the 20th Century, annual aggregate production in the United States amounted to about 50 million short tons. Today annual aggregate production is nearly 2.5 billion tons. Over a third of the States in the country produce more aggregate than the Nation did at the turn of the century. I would like to describe some of the historical events that allowed this nearly 50 fold increase in aggregate production. You might wonder why I want to talk about history. Some of our best ideas lie buried in the past, waiting to be rediscovered in the present. Almost every issue that the aggregate industry experiences today has been recognized for at least a decade; many of those issues have been recognized for a half a century; and a few of them have been recognized for nearly a century. The main reason for this article is to save the past from the forgetful indifference of the present-to faithfully preserve the past, to illustrate the insights of our predecessors, and to demonstrate how little of what we know today is really new.

Jan 1, 1998

By Doandy Yonathan Wibisono

Shotcrete is a versatile and widely utilized rock support material in mining and civil engineering projects due to its adaptability, strength, and efficient application. It immediately stabilizes rock surfaces, effectively controlling loose materials and preventing rockfalls in underground excavations. This paper focuses on assessing and analyzing data from observations of nozzlemen (shotcrete sprayers) during primary ground support activities in an underground mine. The study highlights the importance of nozzlemen’s skills in ensuring the quality of shotcrete application, which is critical for underground mining operations’ structural integrity and safety. A comprehensive training program and field support were implemented to enhance the nozzlemen’s proficiency. The training set covered theoretical knowledge and practical techniques to improve shotcrete application daily. Proficiency improvement was assessed using quantitative metrics, with rebound percentages decreasing by 5–14% as nozzleman competency increased. The results of this initiative showed significant improvements in shotcrete quality, including increased efficiency, reduced waste, and fewer reworks or rehabilitations. The findings aim to contribute to a broader understanding of best practices in shotcrete application and nozzlemen training, ultimately enhancing ground support application measures in the mining industry.

Feb 1, 2025

By A Huebner, A Noack

Companies all over the world are very sensitive concerning their IT and network security. In most network connected technical installations and machines however, network security is not taken into account to a significant extent: insecure protocols are run, unencrypted information is exchanged freely and even broadcasted wirelessly and networked machines are accessible via insecure file transfer protocol (FTP).What happens in case of malfunctions of such technical installations? Who is responsible? Who can be held liable in case of accidents? The first computer worm for automation systems (æSTUXNETÆ) (Symantec, 2010) was discovered during 2010.The paper is intended to create sensitivity among decision makers for potential security and resulting safety leaks and points out the current status quo in technical network security. It outlines best practices for secure networking and procedures for remote access and remote software updates on stationary equipment and mobile mining machinery. It describes how to ensure authentic and genuine configurations and software targets and how to ensure secure communication for autonomous and remote controlled equipment. For such equipment in particular, the following statement should apply: æThere is no safety without network securityÆ.

Sep 26, 2011

By G van Niekerk, M Wortley

Screening is a critical part of many mineral processing circuits and keeping the aperture of the screening media within specification is vital to ensure efficient performance of the processing plant. Typical ways of estimating and/or measuring the wear of the screening media vary from very subjective methods (for instance, using the human eye) to manually checking the width of a few of the more severely worn gaps with a measurement device. Subjective methods can be flawed by human error while manual checking can distort the polyurethane or rubber materials that are used in several types of screening media. All of these errors can cause either premature replacement of panels or, even worse, poor screening of the material.Metso Process Technology and Innovation (PTI) and Metso Screening Media Solutions (SMS) have developed an innovative method that measures screen aperture using advanced image processing techniques. Field trials of the device are presented in this paper, which shows the comparison between the different methods of measuring apertures. Case studies demonstrate how the system, when combined with ScreenTrack, MetsoÆs industry leading maintenance system, and screening media, is providing users with the best possible screening solutions.

Sep 26, 2011

By D. N. Esfahani, K. Khazen, M. Mohammadi

Electrowinning is one of the nickel recovery processes from solutions obtained from the leaching of nickel sources. Every year significant amounts of nickel products are used in various industrial processes and daily life, such as catalysts or batteries, which are a valuable source of nickel for recovery. Nickel purity is also very important in the electrowinning process, because the amount of impurities in nickel such as sulphur, if greater than 100 ppm, make it unsuitable for use in catalysts and plating. Because sulfur is intrinsic to the sulphate electrowinning system, we needed to investigate parameters that can affect the quality and purity of nickel. In this regard, experiments were performed in static and circulating electrowinning processes. A monitoring and circulation system was designed and built to measure voltage, current and temperature as well as to circulate the solution in the system at a specified rate. It was then observed that nickel ion concentration, pH, using the circulation system and additives, were factors affecting the purity and quality of nickel, and in the best case the amount of sulphur in nickel was below 100 ppm. Keywords: Nickel, electrowinning, sulphur impurity

Jan 1, 2020

By Madan M. Singh

This section is unique to the Handbook in that it is the only section that deals with underground excavations for nonmining purposes. The editors were of the opinion that the section should be incorporated because the subject matter covered by the chapters is closely related to mining, and many mining engineers are currently involved in these activities. As we enter the decade of the 1990s activities in this category will increase, enhancing the relevance and utility of the material discussed. As the population increases, especially in metropolitan areas, the necessity to go underground will be greater. At the present time, not only are subsurface shopping malls and pedways connecting buildings becoming commonplace, but structures as diverse as the Civil and Mining Engineering Building on the University of Minnesota campus, a road-and-fleet maintenance facility in Multnomah County, OR, and even an ice cream parlor (Dairy Queen) in northern Wisconsin have been constructed underground. Placing utilities below the surface has numerous advantages and is now customary. Rapid transit and highways through tunnels in urban areas have been the norm for many years, but subterranean stormwater reservoirs, power plants, industrial warehouses, and food storage silos are relatively new innovations. The philosophy of underground defense installations is ancient, but their requirements and designs have trans-formed radically as technology advances. The use of under-ground space for disposition of wastes is modern, since it is recently that environmental concerns and waste disposal costs have assumed increased significance.

Jan 1, 2008

By J. R. Thoenen, B. H. Clemmons, A. H. Reed

"INTRODUCTION AND SUMMARYOverall red-ore reserves in the Birmingham, Ala., area were estimated in 1910 by E. F. Burchard 4/. Since then mining has progressed into areas classed by Burchard as ""unavailable for exploitation"" under conditions existing at that time. This is understandable when it is considered that red iron ore was valued at $1.19 a gross ton at the mine in Birmingham in 19102/ and by 1948 had risen 300 percent; 6/ that skips had replaced cars in slope haulage; that mechanical loading and rubber-tired haulage had replaced hand loading and mule or locomotive haulage; and that other more efficient mining methods had been introduced. Intensive study during the intervening 40 years has been given to ways and means for upgrading the low-grade ores in the area and combining or blending them with raw red and brown ores for improved blast-furnace feed.It is reasonable to expect that future progress in mining efficiency and increased knowledge of the beneficiation characteristics of marginal ores will permit extraction of red-iron minerals now considered uneconomic.The Bureau of Mines has undertaken to restudy iron-ore reserves of the Birmingham area to determine what tonnage and grades of mineral are present; what is necessary to make them amenable to mining; what further advancement is possible in beneficia¬tion methods; and where increased production may be obtained in the area if and when required. This study has been underway for the past 2 years, but research into the beneficiation of marginal ores has been in progress at the Southern Experiment Station for the past 30 years. Many results of that research have been adopted in commercial practice in the area. Other results have not been published but are pre¬sented here in condensed form as an important factor in assessing marginal deposits with respect to their importance as ore reserves.An interim discussion of the salient features of past history and progress, as well as the data developed during the years of research in beneficiation at this station and the present field investigation, will make for a better understanding of the present position as well as be useful in evaluating future potentialities. Discussion in this paper is confined to the main Birmingham Basin area, which contains the largest concentration of hematite ores in the district."

Jul 1, 1953

By Clyde L. Holmberg, Paul Zinner

"INTRODUCTION In view of the large tonnage of low-grade iron ore and iron-bearing material known to exist at the western limits of the Gogebic range, the Bureau of Mines undertook an investigation of the area for the purpose of evaluating the iron-bearing formations as sources of iron for possible future utilization.After 6o years of exploration an, development on the Gogebic range, the area investigated by the Bureau represents the known western limit of direct-shipping ore mined from operations on the Gogebic range.An area about 2 miles in length between the villages of Pence and Iron Bolt in Iron County, Vic., was selected for investigation, and trenches wore excavated through the overburden and fully across the iron-bearing formation to obtain 108 bulk samples for beneficiation tests. Exhaustive tests involving gravity and flotation methods, magnetic separation, and magnetizing roasts followed by magnetic separation were conducted on the samples to determine the ammability of the individual formations and the entire iron-bearing zone to beneficiation.Empirical data on the character and mineral content of the formations arc tabulated herein, as well as the results of the beneficiation tests."

Dec 1, 1947

By Sabri Ergun

Cost estimates and technical feasibility are compared for six chemical coal cleaning technologies. The comparison is based on conceptual application of the chemical cleaning methods for removal of pyritic and organic sulfur from a utility grade bituminous coal. The process layout includes receipt of 8,000 tpd ROM coal, fine coal pulverizing, desulfurization, and preparation of a compacted clean coal suitable for storage and shipment. The methods are: the Magnex iron pentacarbonyl process, the KVB dry oxidation process, the Battelle hydrothermal caustic leaching precess, the TRW Meyers ferric ion leaching process, the Ledgemont oxygen/water leaching process, and the Bureau of Mines/Energy Research and Development Administration air/water leaching process. Capital costs estimated for the desulfurization operation alone, scaled to 8,000 tpd, range between $14 MM and $122 MM, while estimated operating costs for desulfurization alone on the same scale of operation range between $7 and $17 per ton clean coal produced. Relatively little is known about the chemical cleaning of coal, and present cost estimates indicate that the method might not be competitive at its present state of development when used alone to clean utility grade coals for sulfur removal. The principal attractiveness of chemical coal cleaning lies in its potential for combination with physical cleaning to produce cost competitive compliance coals in a combined process with high-Btu yields.

Jan 1, 1977

By John H. Weitz

Dolomite, heretofore regarded merely as a variety of commonplace limestone, has suddenly attained headline prominence, partly because of the increase in demand for dolomite refractories to line metallurgical furnaces now working at an unprecedented rate of activity, but chiefly because it has become an ore of the light-weight metal, magnesium, needed in vast quantities for the manufacture of war machines. A multitude of inquiries, chiefly from war agencies and prespective operators, for data not only on locations of dolomite deposits but on their size and quality, has made it necessary for the Bureau of Mines to assemble all information available on this important subject. From the Bureau's own records, published information, and correspondence, date on locutions, extent, thickness, accessibility, workability, and chemical composition of high-grade dolomite deposits throughout the United states were accumulated for presentation herein. The report includes about 1,000 tabulations of analyses and a map showing locations of the deposits. The uses of dolomite are discussed in Bureau of Mines Information Circular 7192, "Occurrences and Uses of Dolomite in the United-States," published in 1941. The cordial corporation of many State ecological surveys and various individuals who have contributed information is gratefully acknowledged.

Jan 1, 1942

By Paul M. Tyler

The literature on radium is already voluminous, but mcuh of it is too technical to be intelligible to the average reader, and there is no single publication that covers certain economic features of the radium industry. As a result of the renewed interest in the possibilities of domestic carnotite deposits a number of requests have been made to the Bureau of Mines for information, more particularly with reference to the business aspects of the industry. In order to meet this apparent need, the present paper has been prepared from material available in the files of the bureau. The technical data are compiled from various sources and are believed to be reasonably dependable, but the attempt has been not so much to achieve meticulous scientific accuracy as to brim; together facts of industrial significance and popular interest. GENERAL DESCRIPTION Radium is a brilliant white metal that melts sharply at about 700°C. and volatilizes appreciably at that temperature. With an estimated specific gravity of nearly 6.0, it is more than twice as heavy as aluminum and 25 per cent lighter than irons. Although it has been isolated in its metallic state, it is not used in that form, partly because it tarnishes rapidly even in dry air (forming a nitride), partly because of the greater expense of reducing it to metal, and partly because of the difficulty of dealing with such minute quantities of material. It is used always in the form of its compounds, the most important of which from the vie point of utilization are the bromide, chloride, and sulphate.

Jan 1, 1930

By Mandius C. Lundal

This report describes the work done to develop a coal mining machine to increase productivity and recovery from thin seams beyond the highwall, in addition to decreasing the miner's susceptibility to to highwall hazards First, radar transducers were adapted to measure coal thinkness and detect rock and coal interfaces; Then, the radar was incorporated into a cutterhead with steering controls. Next, visual displays were designed to show cutter position in the coal seam, and anticipated change in coal seam inclination, Finally, development of a telemetry system made remote control of the cutterhead possible. Simultaneously, a high-performance extended depth (HPxD) auger machine was designed with an automatic system to handle 600 ft of 36-in, diameter dual spiral flight conveyor sections. A two man crew controls all operations from a weather conditioned cab outside the VDZ, either at night or day time. As a primary mining tool, working 4000 hr/yr (2 shifts/day) recovering 60% of the coal 600 ft beyond the highwall, productlon to 500,000 ton/yr can be achieved. Volume I provides an overview of machine, systems and productivity.

Jan 1, 1977

Advances were made during 19b5 in many phases of a broad program designed to increase efficiency in the mining, preparation, and utilization of coal. Also recorded were achievements in activities devoted to mine health and safety, coal resources, and mine explosives. Featured in this report is a review of progress in environmental studies relating to coal mining and utilization. Environmental projects comprise a comprehensive program to facilitate mine reclamation and reduce air and water pollution associated with extraction and use of coal. Publications cited throughout this report present results of the coal program in greater detail. Organizations, institutions, and companies contributing to the program are listed in appendix A. Centers and laboratories conducting the coal research and related investigations appear in appendix B.

Jan 1, 1966

Advances were made during 19b5 in many phases of a broad program designed to increase efficiency in the mining, preparation, and utilization of coal. Also recorded were achievements in activities devoted to mine health and safety, coal resources, and mine explosives. Featured in this report is a review of progress in environmental studies relating to coal mining and utilization. Environmental projects comprise a comprehensive program to facilitate mine reclamation and reduce air and water pollution associated with extraction and use of coal. Publications cited throughout this report present results of the coal program in greater detail. Organizations, institutions, and companies contributing to the program are listed in appendix A. Centers and laboratories conducting the coal research and related investigations appear in appendix B.

Jan 1, 1966

By J. D. Vincent

The Henderson mine site is located at Red Mountain on the eastern slope of the Rocky Mountains, approximately 50 miles west of Denver, Colorado. The mill site is on the west slope of the Rockies and mine and mill will be connected by an underground railroad. All designs were for a 30,000 ton per day molybdenite processing plant with provisions for future expansion up to 50,000 ton per day if required. This plan did not just happen, but slowly evolved over the course of about three and one-half years. Many plants cannot afford such a delay, but the Henderson project will take about 10 years from the time it was first discovered until production starts, and these 3 !1 years were well spent in determining the best possible plant site and flowsheet. This paper describes some of the problems and the decisions made in arriving at the final location and flowsheet. The paper does not go into the specific details of how protection of the environment went hand-in-hand with all other project considerations. This particular aspect of the planning has been well-reported on other occasions and considerable information on it is readily available.

Jan 1, 1972